Center rest for lathes.



Ne. 7|6,432. Patented Dec. 23, I902. A. KINGSBURY.

CENTER BEST FOR LATHES.

(Application filed may 6, 1901.)

(No Model.)

Warren rates arnr QFFICE.

ALBERT KINGSBURY, OF \VOROESTER, MASSACHUSETTS.

CENTER REST FOR LATHES.

SPECIFIGATIQN forming part of Letters Patent No. 716,432, dated December 23, 1902.

Application filed May 6,1901- Serial No. 59,050. (No model.)

To ctZZ whom, it may concern.-

Be it known that I, ALBERT KINGSBURY, a citizen of the United States, residing at lVorcester, in the county of Worcester and Commonwealth of Massachusetts, have invented anew and useful Improvement in Center Rests for Lathes, of which the following is a specification, accompanied by drawings forming a part of the same, in which- Figure 1 represents a side elevation of a center rest embodying my improvement, with a portion of one of the jaws broken away in order to disclose the bearing or seat of its actuating-worm. Fig. 2 represents a rear view of a portion of my improved center rest. Fig. 3 is a longitudinal sectional view of one of the jaws of the center rest, showing its actuating-worm in full; and Fig. 4 is a sectional view on line at, Fig. 1.

Similar reference letters refer to similar parts in the different views;

The objects of my present invention are to improve the centerrest ofalathebyincreasing its capacity for supporting a wider range of work, to provide means for the ready and quick adjustment for work of different sizes, to provide means for positively operating the jaws in both directions, to increase the longitudinal movement of the jaws, to provide means for readily removing the jaws or for reversing them end for end, to provide improved means for clamping the jaws in position, and in the several novel details of construction and arrangement of parts, as hereinafter described, and pointed out in the annexed claim.

Referring to the accompanying drawings, A denotes the supporting-framework of my improved center rest, provided with the three equidistant radially-adjustable jaws B, capable of radially sliding in ways in the frame A and of being adjustably held therein by means of clips 0 and clamping-screws C. The opposite edges of the jaws B are beveled at B B The beveled edge B of the jaws bears against the beveled edge of a fixed gib D, and the beveled edge B of the jaw receives the pressure of the beveled edge of the clip 0. The opposite edge of the clipis provided with a foot 0 which rests against a shoulder 0' upon the side of the frame A, so that the pres sure exerted by the clamping-screws C will crowd the jaw against the fixed gib D. The under side of each jaw is provided with a series of teeth B Fig. 3, which are engaged by the thread of a worm E, preferably formed integrally with a rotated spindle E and provided with a polygonal head E to receive a wrench, by which the worm is rotated to impart a longitudinal movement to the jaw. The worm E is held in a recess E which holds the worm from longitudinal movement, and the spindle E is journaled in the bottom of a slot E in the face of the frame A.

In assembling the parts of my improved center rest the spindles E are placed in the slots E, with the worms held in the recesses E The jaws are then placed in position with their beveled edges B bearing against the beveled edge of the fixed gib D. The clips 0 are placed between the beveled edges B and the shoulder G and are held by the clamp ingscrews G. The jaws are then radially adjusted until the central bearing-surfaces of their inner ends are brought into contact with the work F, when the clips C are clamped against the jaws B by means of the screws G, therebvholding them firmlyin position. The teeth B extend the entire length of thejaws, thereby increasing the radial adjustment of the jaws by means of the rotating worm E. By loosening the clips 0, however, the jaws may be disengaged from the worms and quickly adjusted for extreme variations in the sizes of the work held, the finer and more accurate adjustment of the jaws being effected by means of the worms E. The loosening of the clips 0 permits the jaws to be readily removed and reversed to enable them to more securely hold work of different sizes, one end of the jaws being beveled to provide a narrow central bearing-surface a, allowing a close approach of the beveled ends of the jaws and allowing them to hold work of small diameter, while the opposite ends of the jaws are provided with a larger central bearing-surface 1), adapted to hold work of larger diameter. The fixed gibD or other projecting parts of the frame A lie in a plane behind that of the sides or faces H of the jaws B, so that revolving work having a large swing may be held in close proximity to the sides H of the jaws without coming in contact with the supporting-framework. The clamping-screws C pass through elongated holes I in the frame A, thereby allowing the clips 0 to be raised above the shoulders C and moved back in order to release the jaws. The radial movement of the jaws in both directions is positively accomplished by means of the worms E, so that the rotation of the spindles E not only serves to carry the jaws against the work, but to remove them therefrom.

The supporting-frame A is divided into two parts, hinged at J and clamped together by a clamp J in the usual and Well-known manner in center rests of this class, and the frame in use is supported upon the ways of the lathe and held by a clamping-bar K and bolt K in the usual manner.

ALBERT KINGSBURY.

Witnesses:

RUFUS B. FOWLER, FLORENCE 0. 000K. 

